What is wrong with my String comparison in Java

I really don't know why my if condition return True on this on. Please someone help me !!

    Event eve = new Event();
    eve.event_tag = "BR";
    ...
    Sys.event_list.add(eve);

And when I use this condition, it return true..

    if(!current_event.event_tag.equals("BR"));{
    ...
    }

Thank you